DEPT OF NEUROLOGY, KING GEORGE HOSPITAL, VIZAG. EMBRYOLOGY OF THE BRAIN
EMBRYOLOGY OF THE BRAIN The neural tube and its subdivisions The neural crest Histological components of the CNS Development of medulla oblongata Development of pons Development of the midbrain Development of the cerebellum Development of the cerebral hemispheres
Dorsal(lateral) alar lamina- caudal bulbopontine extension olivary nuclei Sensory nuclei of cranial n of medulla Ventral(medial) basal lamina- Motor nuclei of cranial n of medulla DEVELOPMENT OF MEDULLA OBLONGATA
TIME TABLE OF IMPORTANT EVENTS Neural plate is formed at the beginning of the 3rd week. Neural folds begin to fuse in the 4th week. The anterior neuropore closes by 25th day and the posterior neuropore closes by 27th day. By the end of the 4th week, the neural tube is fully closed. In the 5th week, brain vesicles have formed and the flexures of neural tube are in progress. Corpus striatum appears in the 2nd month. Corpus callosum forms in the 10th week.
Myelination begins in the 4th month. Differentiation of cerebellum starts in the 8th week. The cerebellar cortex and Purkinje cells appear by the 12th week. Dentate nucleus is seen in the 15th week.